Opposed piston two-cycle engine



April 2 3, 1946.` H, vNRUTl OPPOSED PISTON TWO-CYCLE ENGINE Filed May 15. 1944 'llllllif Patented Apr. 23, 1946 UNITED STATES PATENT OFFICE 2,398,980 i.; oPPosED PIsToN Two-CYCLE ENGINE Hans Vonrti, Winterthur, Switzerland, assigner to Schweizerische Loko motiv-und .Maschinenfabrik, Winterthur, Switzerland Application May 13, 1944,]sei'1No. 535,478 In Switzerland April 8, 1 943 Y 8 Claims. Cl.' v12d-51) 'Ihis -invention relates to two-stroke internalcombustion engines in which two opposed pistons work in each cylinder and the pistons act by the intermediary of links on rocking levers mounted on the xed engine casing. The object of the invention is the provision of an internal-combustion engine of the aforesaid type which occupies a reduced space and is of relatively small weight, While it affords easy accessibility of all parts, particularly of the pistons.` y Y e Y Y According to the invention. four or more working cylinders are disposed substantially in a plane extending at right angles to the crank shaft, the axes of the'cylinders being tangential to at least one circle which is concentric to the axis of the single crank shaft receiving the power of all the pistons.

The accompanying drawing represents by way of example a preferred embodiment of theinvention.

Fig. 1 shows the internal-combustion engine, partly drawn in longitudinal section through the cylinders, and partly in elevation.

Fig. 2 is a plan View drawn in to the line II-II of Fig. 1.

The pairs of pistons I and 2, 3 and 4, 5 and 6, 'l and 8 work as opposed pistons in the cylinders 9, Ill, II and I2, each one of the four cylinders section according comprising one pair of opposed pistons. The

axes of successive cylinders are disposed at right angles one relatively tothe other and extend tangentially with respect to a circle 20 having its centre in the axis 2| ofthe crank shaft and situated in a plane which is perpendicular to this axis. The axes of the cylinders formtogether with their points of intersection a regular rectangle or a square. When the cooperating pistons are in their innermost position, as for example the pistons I and 2 in Fig. 1, the compression space is enclosed between these two pistons and the cylinder wall; when the pistons are at their outer extreme positions, as for example the pistons 3 and 4 in the cylinder- IU, scavenging is effected through the series of ports I3, I4 andthe annular ducts I5, I6. Air enters through one of the two port series, for example, ports I3 and leaves the cylinder through the other series I4. The scavenging pump is diagrammatically represented in the drawing by a centrifugal turboblower 60 and can be driven by an exhaust gas turbine 6I. However, it will be understood that y the particular means for providing scavenging and charging air is of no inmportance so far as the present invention is concerned.

Links I1 are hingedly connected with one end to Cil' the pistons I to 8. AEach two pistons, as the pistons 2 and 3, working in cylinders the ends of Which are adjacent and face each other and forming a right angle one with another, are hingedly connected bymeans of the links I1 to the outer arm -of a common rocking lever I 8. The rocking leverY I8 associated with the pistons 2 and 3 has itshub 22 pivotallyrmounted on a pin 24 secured to the casing 23 and vcarries on its inner end a pin 25, on which the connecting rod 26 isV hingedly mounted;l The head l2'l'of the connecting rod is engaged on 'afcrank pin 28 of the crank shaft 30.

The outerfends of the rocking levers are forked,

the fork -portions 3I-being so spaced that after removalof the pins 32 connecting the link I1 to ther` rocking lever |8, the respective link together with-'the piston can be withdrawn from the cylinderwithoutethe rocking lever interfering with such removal. At the outer ends of the rocking levers, removablegcovers 33 are provided for the purposes of withdrawal of the pistons. The pins 32 can be dismounted after removal of the lateral covers 46. f f f Whil'ertherocking lever I8 is associated with the 'pistons 2 vand 3, and connected to the crank pin 28Y by means of the connecting rod 26, the rocking lever 34 associated withy the pistons 6 and 1,` has its inner arm connected to the crank pin 36 b y means lof the connecting rod 35, this crank pin 36`being displaced through 180 with respect tothe 'pin` 28. Therocking levers' 39 and 40, indicated in dash and dot lines only in Fig. land associated with the pistons 8, I and 4, 5, respectively, act bymeans of connecting rods 4I and 42, respectivelyfnthe crank-pins 43 and 44. Obviously,` theA innerends of the rocking levers 39 an'd40 are situated in the same plane perpendicu- Llar` .tothe crank shaft 30 as'the corresponding crank pins 4 3 angl-44; the inner end of the rocking lver'39 is represented in dash and dot lines in'Fig.' 1Z'in substantially the position in which itl'arrivs during thescavenging period in the cylinder`9. A

The flange 45 of the crank shaft may be connected with a` fly wheel, In addition to the series of cylinders 9 to I2, there can beY provided Ya second series of four cylinders also 4disposed in a plane perpendicular to Vthe crank shaft axis, which second series would be placed axially behind the cylinders 3 to I2 in Fig.,1 and positioned in the same manner as these latter; two cylindersf5l and 52 of this second series of cylinders arel represented in plan view in Fig. 2l In order to connect the pistons of these cylinders to the corresponding rocking levers, the hubs 22 of the levers are provided with additional forks 3io, as Y represented in Fig. 2 for the rocking levers I8 and 34.

Instead of providing only four cylinders, the engine can comprise five, six or more cylinders disposed in the same plane. In this case the axes of the cylinders form a polygon which can be regular or irregular. It will, howeven'be recognized, that-the utilization of thev transmission linkage will be most effective when providing an even number of cylinders, although it will be possible, as mentioned, to construct the internal combustion engine according to the invention with an uneven number of cylinders.` Preferably the series of cylinders are so disposed that one corner of the polygon formed by the cylinder axes is downwardly directed, or that this corner is situated vertically beneath the centre of the polygon. In this case all injection nozzles placed in the middle of the cylinders are easily accessible. When however the polygon is so situated that one side thereof extends horizontally and forms the baseof the polygon, then all the pistons are readily accessible.

It is to be understood that the above disclosed structurer is merely illustrative and that various changes and modifications may be made-in the practice of my invention without departing from the scope of the appended claims I claim:

1. A ltwo-stroke internal-combustion engine of the opposed piston type comprising at least four cylinders substantially disposed in the same plane, two opposed pistons working in each cylinder, a single crank-shaft means connecting the pistons of all cylinders with said crank shaft, said crank shaft extending at right angles to the plane of the cylinders, and the axes of the cylinders being tangential to a circle disposed coaxially with the crank shaft.

2. A two-stroke internal-combustion engine of the opposed piston type comprising at least four cylinders substantially disposed in a single plane, two opposed pistons working in each cylinder, a

single crankshaft extending at right. angles to n theplane of the cylinders, and means operatively connecting the pistons of all cylinders to said crank shaft, the axes of the cylindersV being tangential to a circle disposed coaxially with the crank shaft, said axes forming with their points of intersection a regular polygon having the axis of the crank shaft passing through ,the center thereof. i

3. AHtwo-strokeinternal-combustion engine of Y the opposed piston type comprising a plurality of series of at least four cylinders, the different series of cylinders being substantially disposed in single parallel planes, two opposed pistons. Working inleach cylinder, a single crank shaft extending at right angles to said parallel planes of thek cylinders, and means operatively connecting the pistons of all series of cylinders to said crank shaft, the axes of the cylinders of each'` series being tangential to a circle disposed in the respective plane of the cylinders and coaxially with the crank shaft.

4. A two-stroke internal-combustion engine of the opposed piston type comprising at least four cylinders substantially disposed in a single plane, two opposed pistons working in each cylinder, a single crank shaft means including connecting rodsconnecting the pistons of all cylinders with said crank shaft, said crank shaft extending at right angles to the plane of the cylinders, the cylinders having their axes disposed tangentially to a circle whose center lies in the axis of the crank shaft, and a common rocking lever operatively connected to two pistons of the opposite ends of each two successive cylinders and to the crank shaft for transmitting the forces of said pistons to the crank shaft.

5. A two-stroke internal-combustion engine of the opposed piston type comprising at least one series of at least four cylinders disposed in a single piane,ptwo opposed pistons working in each cylinder, a single crank shaft extending at right angles to saidplane of the cylinders, the cylinl5y intersecting at an angle of at least a common Y rocking lever operatively connected to two pistons working in opposite sides of each two successive cylinders, and a, connecting rod disposed between each rocking lever and the crank shaft to transmit the forces of said two pistons to the crank shaft. i

6. A two-stroke internal-combustion engine of the opposed piston type comprising at least four cylinders disposed in a single plane, two opposed pistons working in each cylinder, a single crank shaft extending at right angles to said plane of the cylinders, said cylinders havingy their axes disposed tangentially to a circle whose center lies in the axis of the crank shaft, rocking levers for transmitting the forces` of the pistons to the crank shaft, a link connecting each piston to a rocking lever, said rocking levers having a, forked end, and a pin carried by the forked end of the rocking levers to hingedly connect said link to the lever, the two branches. of the forked end of the rocking levers being so spaced that after withdrawal of said pin the pistons can be removed fromthe cylinders without the rocking levers interfering with such removal. Y

7. A two-stroke internal-combustion engine of theopposcd piston type comprising at least four cylinders disposed in a single plane, two opposed pistons working in each cylinder, and a single crank shaft extending at right angles to said plane of the cylinders, said cylinders having their axes disposed tangentially to ya circle whose center lies in the axis of the crank shaft whereby `the axes ofv the cylinders with theirA points of intersection form a polygon, and the cylinders being disposed in a vertical plane and in such relation with respect to said circle that one corner ofV said polygon is situatedr vertically below the center of the polygon. 1 i

y8. A two-stroke internal-combustion engine of the opposed piston type comprisingv at least: four cylinders'disposed in a single plane, twoopposed pistons working in each cylinder, a single crank shaft extending at right angles to said' plane of the cylinders, and means operativelyV connecting the pistons of all cylinders to the crank shaft, said cylinders having their axes disposed tangentially to a circle whose center lies inthe axis of. the'crank shaft whereby theiaxes of the cylinders with their points of intersection forma polygon,l and the cylinders being disposed in a vertical plane and in such relation with respect to said circle that one side of said polygon extends horizontallyas base of the polygon.

HANS voNR'rI. 

